Furnace for roasting zinc blende



G. BALZ FURNACE FOR ROASTING ZINC BLENDE Dec. 15, 1931.

Filed Jul 7, 1926 2 Sheets-She'et 1 57 0 5 V 9 WW 2 6 m ATTJRTVEY Patented Dec. 15, 1931 PATENT OFFICE GEORG BALZ, OF GLEIWTTZ, GERMANY FURNACE FOB BOASTIDTG ZINC BLENIDE Application filed July 7, 192 6, Serial No. 121,010, and in Germany December 5, 1925.

This inventionrelates to a furnace for roasting zinc blende.

In particular, the invention deals with a furnace which is traversed by the blende from 'sthe top towards the bottom, and in which the blende is washed by furnace air moving in the o posite direction, whereby merely a portion of the air is introduced as the material is discharged from pro-heated chambers situated at the'hearth level, and the remainder supplied in the'form of cool, fresh air through passages beneath the arch of the furnace, striking against the material falling freely out of .the central opening of the hearth, in this manner any. parts endangered by the heat being cooled, sintering and agglomeration of the blende prevented, and the material -made better suitable for purposes of smelting. 1 Now it is desirable for the draft in the furnace to be maintained as constant as possible. Particularly in the case of the floors or compartments at which the blende moves in an upwardly inclined direction it is shown that 2 by reason of the known method of conveying the material and transferring the same from the one floor to that located thereunder, which is effected by means of vanes or the like of refractory material mounted at the top of each compartment, mounds or accumulations of blende very readily tend to form, which extend as far as the top of the compartment and choke the draft, so that the proper functioning of the furnace is very greatly affected, or even rendered impossible. A regular craft in the furnace is absolutely nec-. essary both as regards quality as well as quantity of the product.

The main object of the invention is to en-- sure that a proper draft is maintained, this being accomplished by providing on the roof of the arch scrapers which, when ac,- cumulations are formed strike ofl' the mounds and at the same time better distribute the material. a

The secondary air is introduced from above or from below or from the side towards a slotted cage in the inner-passage where the material changes its direction. The air now meets from the inside not only against the material falling freely through the hearth opening, but also against the sliding material moving towards the passage, the action of the-air thus being considerably increased and improved. The seconda air if coming from the top is preferably introduced through a feedpipe passed through the gas discharge, the same being taken through an opening in the arch above the centre passage, and, as stated above, furnished'at it slower end with 60 a suitable, slotted cage through which the air is emitted. The slotted cage is preferably normally closed at the bottom in order to prevent the air from passing out in an axial direction and to compel the same to pass out laterally in order, proceeding from the interior, to meet on all sides against the material falling through annularly and against the material conveyed towards the opening. This method of supplying the air assists also to (0 improve the draft. 1

If the air is introduced to the distributing member from the bottom or from the side, the

' feed pipe maycpe passed through the furnace point, and the arrangement p at any desire may be of such kindthat branch pipes, each capable of regulation per so, may be attached to the vertically or obliquely disposed. main supply pipe, so that air may be passed from p the one or other point according to require- .ments to the distributor, and accordmgly against the blende inthe furnace; or a mixture of air may be introduced as determined by manipulation of the regulators. If necessary, introduction of the air in a lateral di- 3 rection may also be combined with introduction from. below, or'also from above. A form of embodiment of the invention is illustrated by way of example in the accompanying drawings, in which n Figure 1 is a vertical'section of the furnace. Figure 2 is a cross-sectional view of the furnace on line 22, Fig. 1. a

Figure 3 is a vertical section of the cage on line 33, Fig. 5.

Figure 4 is a vertical section of the furnace showing a modification thereof.

Figure 5 is a cross-sectional view on; line 55ofFigure3. I

With reference to Fig. 1, the blende passes from compartment to compartment througlh the openings 7 and 9. On the roof of t e arch are furnished in known manner vanes or other conveying means '6 for moving the blende towards the openings 7 and 9. The furnace comprises discs 11, 12, 13, 14 and 15 which form compartments and which are made of any suitable refractory material.

Alternate discs 11, 13 and 15 are stationary and are supported by columns 10. Discs 12 and 14 are rotatably mounted on tracks 18 by means of rollers 17, said discs are encircled by toothed driving rings 16. A shaft 19 rotated by any suitable means has pinions 15 20 keyed thereon so that discs 12 and 14 may be rotated. Said conveying means 6 which may have a wedge formation are mounted on the underside of alldiscs except disc 15. In the caseof the compartments in which the m blende moves in an upwardly inclined direction, i. e., towards the opening 9, accumulations are very easily formed which may extend right to the top of the compartment, and which then choke the draft and considg5 erably aflect operations, or evenblock the furnace.

An essential feature of the invention resides in the provision of the scrapers 35,

ccording to Fig. 1 an air supply pipe 36 is. passed through the upper compartment 5 and the arch thereof, being taken through the gas discharge and made to be movable in any suitable manner at 37. The pipe 36 may open out in front of the central opening 9, or may be extended to any desired degree within the same. At the lower end of 36 is situated a slotted cage 38, through the slots 42 of which the air is forced on all sides in the desired direction, this cage being preferably closed at the bottom in order to prevent the air from passing outin an axial direction.v The air strikes against the material falling in annular form at 9, and also against the blende being conveyed towards 9, and the cooling eifect is greatly improved. The cage may be of any desired size, or the same may also comprise the lower end of the feed pipe itself.

- In the form of embodiment according to Fig. 3 the end of the pipe 36, or a tubular portion aflixed thereto, is slotted or cut longitudinally, and the tongues 43 so formed are secured by means of rings applied either interiorly or exteriorl ,these rings being designated 39. An opening in the bottom of the skirt is closed by means of a temporary insertion ball 40, so that the cage may be cleaned from below by introduction of an air blast and dis lacement of said ball 40.

According to ig. 4, the air may be introduced from below (pipe 36), or from the side (pipe 31), either terminating in the slotted cage 38'. The ipe 36' may be bent at a suita 1e angle, or ranch pipes 41. may be provided in any desired number, which are furnished with regulating members 33, and through which the secondary air may be introduced at suitable pressure.

What I claim as new and desire to secure by Letters Patent is:

1. In a furnace for roasting zinc blende, in combination, a plurality of circular refractory'discs placed in spaced relation to form intervening chambers, meansfor rotating alternate discs, wedge shaped vanes ositioned on the lower surfaces of said discs and scrapers positioned on said discs for destroying accumulations of the blende.

2. In a furnace for roasting zince blende, in combination, a plurality of circular refractory discs placed in spaced relation to form intervening chambers, means for rotating alternate discs, wedge shaped vanes positioned on the lower surfacesof said discs, scrapers positioned on said discs for destroying accumulations of the blende and a means for introducing air directly into the furnace at the axisthereof. I

3. In a furnace for roasting zinc blende, in combination, a plurality of circular refractory discs placed in spaced relation to form 1 intervening chambers and provided with a plurality of openings, means for rotating alternate discs, an air supply pipe coaxial with respect to said furnace, a cage positioned on the discharge end of said air supply pipe, :1 10:; gas discharge pipe communicating with said intervening chambers, vanes and scrapers positioned on said discs to propagate the blende and destroy accumulations thereof respectively.

4. In a i furnace for roasting zinc blende, in combination, a plurality of circular refractory discs placed in spaced relation to form intervening chambers and provided with a plurality of openings, means for ro- 1l 5 tating alternate discs, an air supply pipe coaxial with respect to said mace, a cage positioned on the discharge end of said air supply pipe, said cagebeing provided with a plurality of vertical slots forming tongues, a plurality of rings engaging said tongues,

a gas discharge pipe communicating with said'intervening chambers, vanes and scrapers positioned on said discs to propagate the blende and destroy accumulations thereof respeetively.

' 5. In a furnace for roasting'zinc blende, in combination, a plurality of circular refractory discs placed in spaced relation to form intervening chambers and provided with a plurality of openings, means for rotating al-. ternate discs, an air supply pipe coaxial with respect to said furnace, a cage positioned on the discharge end of said air supply pipe,

3 said cage bem provided with a p urality of vertical slots orming tongues, said cage being further provided with a hole in the bottom thereof and a ball ada ted to normally close said cage, 9. gas disc arge pipe communicating with said intervening chambers, -vanes and scrapers positioned on said discs to ropagate the blende and destroy accumulations thereof res ivelg. In testimony w ereof have aflixed my ature.

slgn m GEORG BALZ. 

